Saw tooth setting machine



April 1950 B. N. ENGLE ET AL 2,504,393

SAW TOOTH SETTING MACHINE Original Filed July 5, '1945 Patented Apr. 18, 1950 SAW TOOTH SETTING MACHINE Burr N. Engle and John B. Engle, Los Angeles, Calif.

Original application Jul 603,288, now Patent N y 5, 1945, Serial No. dated May 11', 1948. Divided and this application March 23, 1948, Serial No. 16,514

3 Claims.

This application is a divisional application of Serial Number 603,288, filed July 5, 1945, which matured as Patent No. 2,441,403, dated May 11, 1948, entitled Teeth setter for saws.

This instant application concerns the auto matic setting of teeth by breaking the light beam from a suitable source, the beam being broken by the teeth of the saw being set so that the saw need only be slid alon a certain path in order to operate the sawsetting machine accurately.

The automatic saw setting device of this inven tion includes a hammer element for bending every other tooth to one side of the saw blade, the hammer being controlled in its action by the saw teeth themselves.

One of the principal objects of this present invention is to present a new and novel teeth setting machine that is simple and sturdy in corn struction, easy to operate, automatic in its operation, substantially fool-proof, and which is eco nomical to make and manufacture.

Another object is to provide an automatic teeth setting machine in which the operator need only run the blade of the saw along a pair of guides in order to fully set the teeth of the saw, the teeth i being set at a rapid pace and done in a perfect manner.

Other objects, advantages and features of our invention will appear from the accompanying drawings, the written subjoined detailed descriptlon, the preamble of these specifications, and the appended claims.

Applicants are now about to illustrate and describe one form of their invention in order to teach one how to make and, thoroughly use the same, but it is to be understood that the drawings and description thereof are not to limit the invention in any sense whatsoever, except as limited by the appended claims.

It is well known to applicants that various changes and modifications may be made in the details of form, style, design and construction of the'whole or any'part of the specifically described embodiment of this invention without departing from the spirit thereof, such changes and modifications being restricted only by the limitations clearly expressed in the following claims.

In this particular form. of the invention, Figure 1 of the drawings shows a schematic layout of the electrical circuits involved and the various elements connected therewith,

Figure 2 is a vertical sectional view of an electromagnet to be employed in this invention.

The hammer 33 at the saw location was broken away so that the balance of the hammer and the electromagnet 3 could be placed in a better position for the sake of clarity in illustration of the entire device.

The coil 3 has a number of takeoff taps contactable by a switch arm 12 which is pivoted at 13 to any portion of the device. The other end of the coil winding has a lead 14 which extends therefrom and which makes connection with the electrical conductor l5, and this conductor connects with one side of a double pole switch 16. The live side of this same switch has connection with an electrical conductor Tl that leads to one side of a suitable source of electric current supply such as the usual house alternating current Of cycles at 110 volts The other wire from the supply is indicated at 78 and connects with'the' other terminal of the switch 16, and from which switch a conductor l9 extends; the conductors l5 and 19 being the main current supply for the electrical equipment of the circuit.

Between the pivot 13 and the main conductor 19 there is a rotary switch 89 designed to alter nately turn on and off current to the solenoid or close the conductors BI and 82. A hand operable switch is shown in parallel at 83 so that the plunger or hammer 33 of the solenoid can be worked independently of the automatic switchmeans 80.

The switch means is operated by an electromagnet 84 which has its coil connected in the main supply line 19. The extended core of the electromagnet, when energized, attracts the armature 85 which is fixed at the point 86; a stop 8? limiting the distance the armature 85 can space itself from the core of the electromagnet.

At the free end of the armature 85 there is a vertically movable bar having on the top end thereof a dog or detent 88 which is arranged and adapted to move a toothed wheel 89 one tooth each time the detent is pulled downwardly by the armature 85 when it is released by the electromagnet. The detent is made flexible so that on the upward stroke, it can clear the tooth just above it in a manner well known in mechanical arts. An extended disc at one side of the wheel 89 has a plurality of current conducting segments 9i) insulated from each other and spaced apart so that a, contact rider 9| will alternately be on and oil a segment as the disc is intermittently rotated by the detent 8&3, that is, one tooth at a time. The contactor 9! is fired to one end of a spring band 92 which is in turn fixed to a point 93 where it connects with the conductor 8!. A branch conductor 9iconnects the conductor 82 with all the segments 93 of the disc. The electromagnet 84 cannot operate unless the contacts 95 and 96 are closed by the micro-switch 9'? which is operated by the midget electromagnet 98, as shown.

The micro-switch 91 is operated by an electric eye device which is controlled by the teeth in the saw Til. The reference character H35 represents. a photo-electric cell having a cathode 102 of sodium, potassium, or other metal which gives off electrons when subjected to the influence of light,

and an anode I03. A battery I04 is placed in the circuit with this cell and the current which passes through the cell when exposed to the influence of a light source, the small incandescent lamp I05 for example, is caused to flow through the high resistance I06. In conjunction with this source of small currents there is employed an electron discharge tube I01 comprising a cathode I08 of filamentary form provided with means for heating it which may consist of the battery I09, or the low side of a low voltage transformer, an anode H and a conducting body III in the form of a grid interposed between the cathode and the anode.

In circuit with the cathode and the anode is placed a battery or other source of current I I2 and a resistance H3, the value of which bears a given ratio to that of the resistance I06. In series with the battery I I2 there is the coil of the midget electromagnet 98.

By the above arrangement of the electrical units, the midget electromagnet will be energized only when a beam of light from the source I reaches the light sensitive cell HM and which maintains the contacts 96 and 95 open until the light beam is broken by the point of one of the saw teeth. When the beam of light is broken, the electromagnet 84 raises the armature 85 while the heavy power current passes through the large solenoid 3 and forces the hammer 33 onto an unset tooth of the saw. When the beam of light again reaches the cell IOI, the spring armature is again raised by the midget electromagnet 98 and causes the contacts 95 and 96 to open, which action tie-energizes the electroma net 84 to release the armature 85. When this armature is released, it returns to the stop 81 and slightly rotates the toothed wheel 89 just far enough to place the contact rider 9I on an insulated space of the disc so that the next tooth of p the saw, which must be set in the opposite direction, is not set by the next breaking of the beam of light, that is, the hammer 33 cannot operate when the contact rider is not on a segment 90. In this manner, every other tooth of the saw is set, and when it is desired to set the other teeth, the saw is turned over and run through the device again.

In order to assure exactness, so that the beam of light will be broken only near the tip or point of the saw teeth, the light source I05 is placed in a light sealed box II I provided with a very small slit for the light to escape and strike the cell WI. The light cell itself is also placed in the same kind of a box or cover with a small slit for the light beam to enter. This is done so that other sources of light will not operate the electric eye device.

In Fig. 2 of the drawings, there is shown a preferred form of a hammer and magnet arrangement that may be used most successfully in this invention and which forms a part thereof. The magnet is indicated at I and it has an iron clad shell I2I in which there is a through bore I22 adapted to accommodate the sliding plunger or armature I23 and the adjustable magnetic intensifying threaded plug I24 which is slotted at I25 to receive an end of a screw driver so that the plug can be adjusted like a set screw. Within the shell there is the electrical winding I26 having its ends I21 and I28 passing through the shell for connection with a suitable source of electric current that has an electric switch so that the magnet can be operated at will by merely closing the switch.

iii

At one end of the magnetic plunger I23 there extends an arm I20 having at its end the biased hammer head portion I30, the slanted surface of which is adapted to bend a tooth of a saw against the slanted surface of the anvil part I3 I, the anvil being securely fixed to a suitable support and the plunger I23 provided with proper guides so that the work of bending the teeth on a saw will be perfect.

We claim:

1. The device recited in claim 2 wherein the hammer means comprises a plunger in the bore of a solenoid and wherein one end of the bore is closed by an adjustable intensifying plug, one end of the plunger having a biased portion facing toward the solenoid which is adapted to set teeth of a saw against an anvil having a like surface faced in the opposite direction.

2. In a means for setting the teeth of saws which includes a support having saw guide means for alining a saw in the path of a control light beam and in the path of a saw setting hammer means, an electromagnetic hammer means positioned upon the support and alined to strike single teeth of a saw and bend them, an electrical circuit including an electric eye unit and an intermittent operative switch in series with the electromagnetic hammer means, means for operating the intermittent operative switch which is in series with a control switch that is operated by a micro-switch under the control of the electric eye unit, the aforementioned parts operating so that each saw tooth upon interrupting the light beam of the electric eye unit causes the electromagnetic hammer means to operate at every alternate light beam interruption by action of the intermittent operative switch.

3. In a means for setting the teeth of saws which includes a support having saw guide means for alining a saw in the path of a control light beam and in the path of a saw setting hammer means, an electromagnetic hammer means positioned upon the support and alined to strike single teeth of a saw and bend them, an electrical circuit including an electric eye unit and an intermittent operative switch having a ratchet means for its operation and wherein this switch is in series with the electromagnetic hammer means, solenoid means for operating the ratchet means, a micro-switch under the control of the electric eye unit and which micro-switch has a heavy current switch that is operated thereby, and which heavy current switch is in series with the solenoid, all the aforementioned elements operating so that each saw tooth upon interrupting the light beam of the electric eye unit causes the electromagnetic hammer means to act at every alternate light beam interruption through the action of the intermittent operative switch.

BURR N. ENGLE. JOHN B. ENGLE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 839,909 Watkins et al. Jan. 1, 1907 1,152,256 Worthington Aug. 31, 1915 2,284,557 Brackett May 26, 1942 2,371,358 Sekells Mar. 13, 1945 

